Gear unit for manual or motor-driven cable window lift systems

Abstract

Gear unit and motor-driven gear unit for cable window lift system of motor vehicles, comprising drive and gear mechanism which cooperates with the drive and is coupled to rotatably mounted cable drum for winding/unwinding a cable of the system. Diameter of the cable drum of the gear unit ranges from about 22 mm to about 30 mm, preferably from about 24 mm to about 28 mm; gear ratio of the gear mechanism ranges from about 1:38 to about 1:55, preferably from about 1:42 to about 1:51. The cable drum has, on its end face, claws which engage in corresponding recesses on the end face of a worm wheel. Electric motors having maximum driving torque of only about 5.7 Nm can be used. The gear unit size can be reduced by about 40-50%, and it can be standardized for both electric and manual cable window lift systems for front or rear vehicle doors.

1 . A gear unit for cable window lift systems of motor vehicles, comprising a drive and a gear mechanism, wherein 
 said gear mechanism cooperates with the drive and    a driven worm wheel of said gear mechanism is coupled to a rotatably mounted cable drum for winding and unwinding a cable of the cable window lift system, in which gear unit    a diameter of the cable drum is in a range from 22 mm to 30 mm and    a gear ratio of the gear mechanism is in a range from 1:38 to 1:55.    
     
     
         2 . The gear unit as claimed in  claim 1 , wherein the diameter of the cable drum is in a range from 24 mm to 28 mm.  
     
     
         3 . The gear unit as claimed in  claim 2 , wherein the gear ratio of the gear mechanism is in a range from 1:42 to 1:51.  
     
     
         4 . The gear unit as claimed in  claim 1 , which gear unit can be used optionally for one of an electric drive and a manual drive using an identical cable drum.  
     
     
         5 . The gear unit as claimed in  claim 1 , which gear unit can be used optionally for one of a cable-operated window lift system for a front motor vehicle door and a cable-operated window lift system for a rear motor vehicle door without further design modifications.  
     
     
         6 . The gear unit as claimed in  claim 1 , wherein said worm wheel is accommodated in a housing section of said gear unit, 
 wherein above a toothing of said worm wheel opposite to an upper edge of an inner peripheral wall of said housing section said worm wheel has a smooth-walled peripheral edge and    wherein a sealing means is provided for sealing an annular gap formed between said smooth-walled peripheral edge of said worm wheel and said upper edge of said inner peripheral wall of said housing section and for sealing off the worm wheel with respect to the housing section such that a front face of said worm wheel is exposed to an outer side of said housing section and    wherein said cable drum is disposed at said outer side of said housing section.    
     
     
         7 . The gear unit as claimed in  claim 6 , said sealing means comprising hook-like protruding sealing lips bearing against one of the upper edge of said inner peripheral wall of said housing section and said smooth-walled peripheral edge of said worm wheel for sealing off said worm wheel with respect to said housing section.  
     
     
         8 . The gear unit as claimed in  claim 6 , wherein the sealing means embraces an upper edge of the housing section or of the worm wheel and is seated on the upper edge in a frictional-tight manner and such that it is fixed in rotation.  
     
     
         9 . The gear unit as claimed in  claim 8 , said gear unit including said housing section and said sealing means being formed by a two-component injection molding process for forming said gear unit including said housing section from a first rigid plastics material and said sealing means from a second plastics material softer than said first plastics material.  
     
     
         10 . A motor-driven gear unit for cable window lift systems of motor vehicles, comprising an electric motor and a gear unit, said gear unit comprising a drive and a gear mechanism, 
 said gear mechanism cooperating with the drive and a driven worm wheel of said gear mechanism being coupled to a rotatably mounted cable drum for winding and unwinding a cable of the cable window lift system, in which gear unit:    a diameter of the cable drum is in a range from 22 mm to 30 mm; and    a gear ratio of the gear mechanism is in a range from 1:38 to 1:55;    in which motor-driven gear unit said electric motor is coupled to the gear unit, and    a driving torque of the electric motor is at most 5.7 Nm.    
     
     
         11 . The motor-driven gear unit as claimed in  claim 10 , wherein an output power of the electric motor is at most 10 W.  
     
     
         12 . The motor-driven gear unit as claimed in  claim 11 , wherein the electric motor can be used optionally for a cable window lift system for a front motor vehicle door and for a cable window lift system for a rear motor vehicle door without further modification of the gear unit.  
     
     
         13 . A motor-driven gear unit for cable window lift systems of motor vehicles, comprising an electric motor and a gear unit, said gear unit comprising a drive and a gear mechanism, said gear mechanism cooperating with the drive and a driven worm wheel of said gear mechanism being coupled to a rotatably mounted cable drum for winding and unwinding a cable of the cable window lift system, in which gear unit: 
 a diameter of the cable drum is in a range from 22 mm to 30 mm; and    a gear ratio of the gear mechanism is in a range from 1:38 to 1:55;    in which motor-driven gear unit said electric motor is coupled to the gear unit, and    an output power of the electric motor is at most 10 W.    
     
     
         14 . The motor-driven gear unit as claimed in  claim 13 , wherein the electric motor can be used optionally for a cable window lift system for a front motor vehicle door and for a cable window lift system for a rear motor vehicle door without further modification of the gear unit.